Video streaming, data streaming, and broadband digital broadcast programming are increasing in popularity in wireless network applications, e.g., Internet protocol (IP) multicast services. To support these wireless applications, wireless broadcast systems transmit data content that support data services to many wireless terminals simultaneously. A wireless broadcast system typically comprises a plurality of cells, in which data content is distributed by a service source through a backbone network. Wireless broadcast systems are typically unidirectional networks, in which there may not be an uplink channel (i.e. wireless terminal to serving cell) available.
A Digital Video Broadcast (DVB) system is one example of a wireless broadcast system. A DVB system may support different video services including MPEG-2 multi-media services. A DVB system typically includes multiple cell transmitters (up to hundreds) that provide RF coverage for each cell. Moreover, in order to provide supplementary coverage in a cell, repeaters may be deployed to fill-in RF coverage holes. Each transmitter and repeater typically utilizes a modulator in order to modulate a transmitted radio signal with data content and service information.
Often, the transmitter configuration of a DVB system is changed in response to the dynamic nature of the environment. For example, different digital services that are broadcast at different times may require different data rates, thus requiring modulators to be reconfigured. Also, RF propagation conditions may vary with time, thus necessitating a reconfiguration of the cell transmitters. In a DVB system, the cell transmitters and repeaters are often configured from a central location such a network element manager. However, when a DVB system has many cell transmitters and repeaters that require reconfiguration, synchronizing the configuration of the modulators with the configuration of PSI/SI (program specific information/service information) generators in real time is difficult, particularly since PSI/SI generators are, in general, separate entities from the network element manager. Other reasons for reconfiguration include adding cells in order to create a denser network for better coverage, which may lead to frequency re-assignment. The need for improvement of quality of service may necessitate changes in modulation parameters.
What are needed are systems and methods that facilitate the reconfiguration of constituent modulators in a wireless broadcast system such as a DVB system and preserving the synchronization with PSI/SI at all times.